Ai. Zouboulis et Ka. Kydros, USE OF RED MUD FOR TOXIC METALS REMOVAL - THE CASE OF NICKEL, Journal of chemical technology and biotechnology, 58(1), 1993, pp. 95-101
The presence of red mud was found to remove effectively nickel ions fr
om dilute aqueous solutions (50 mg dm-3). Red mud, being an industrial
solid by-product/waste from alumina production during bauxite process
ing, was found to act simultaneously as an alkalinity regulator, causi
ng precipitation of nickel as the insoluble hydroxide, as an adsorbent
of the formed nickel hydroxide and as a flocculant of the resultant f
ine particulate matter. Sedimentation was subsequently considered as a
possible solid/liquid separation technique. Various parameters, such
as dispersion pH, red mud and nickel concentrations and zeta-potential
, were examined and promising results were obtained.